We evaluated the effects of a chemical additive on the microbial communities, fermentation profile, and aerobic stability of whole-plant corn silage with or without air stress during storage. Whole-plant corn was either untreated or treated with a chemical additive containing sodium benzoate, potassium sorbate, and sodium nitrite at 2 or 3 L/t of fresh forage weight. Ten individually treated and replicated silos (7.5 L) were made for each treatment. Half of the silos remained sealed throughout a 63-d storage period, and the other half was subjected to air stress for 2 h/wk. The composition of the bacterial and fungal communities of fresh forage and silages untreated or treated with 2 L/t of fresh forage weight was analyzed by Illumina Miseq sequencing. Treated silage had greater (P < 0.05) aerobic stability than untreated, even when subjected to air stress during storage, but the numbers of yeasts culturable on selective agar were not affected. However, the additive reduced the relative abundance of the lactating-assimilating yeast Candida tropicalis (P < 0.01). In air stressed silages, untreated silage had a greater (P < 0.05) relative abundance of Pichia kudriavzevii (also a lactate assimilator) than treated silage, whereas treated silage was dominated by C. humilis, which is usually unable to assimilate lactate or assimilates it slowly. The additive improved aerobic stability by specifically preventing the dominance of yeast species that can consume lactate and initiate aerobic spoilage. To the best of our knowledge, this is the first work that identifies the specific action of this additive on shifting the microbial communities in corn silage.

中文翻译：

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化学添加剂对贮藏期间有或无空气压力的玉米青贮饲料的发酵、微生物群落和需氧稳定性的影响。

我们评估了化学添加剂对储存过程中存在或不存在空气压力的全植物玉米青贮饲料的微生物群落、发酵特征和需氧稳定性的影响。整株玉米要么未经处理，要么用含有苯甲酸钠、山梨酸钾和亚硝酸钠的化学添加剂以 2 或 3 L/t 鲜牧草重量处理。每种处理都制作了 10 个单独处理和复制的筒仓 (7.5 L)。一半的筒仓在 63 天的储存期内保持密封，另一半在空气压力下持续 2 小时/周。通过 Illumina Miseq 测序分析未经处理或用 2 L/t 新鲜牧草重量处理的新鲜牧草和青贮饲料的细菌和真菌群落的组成。处理过的青贮饲料比未经处理的青贮饲料有更高的（P < 0.05）有氧稳定性，即使在储存过程中受到空气压力，但可在选择性琼脂上培养的酵母数量不受影响。然而，添加剂降低了泌乳同化酵母热带念珠菌的相对丰度（P < 0.01）。在空气胁迫的青贮饲料中，未经处理的青贮饲料比处理过的青贮饲料具有更高（P < 0.05）Pichia kudriavzevii（也是一种乳酸同化物）的相对丰度，而经过处理的青贮饲料以 C. humilis 为主，后者通常无法同化或同化乳酸慢慢地。该添加剂通过专门防止可消耗乳酸并引发有氧腐败的酵母物种的优势来提高有氧稳定性。据我们所知，这是第一项确定这种添加剂在改变玉米青贮饲料中微生物群落的具体作用的工作。